exists and is an alternate of . Since this is regarding statistics I assume you mean lower case sigma (Ï) which, in statistics, is the symbol used for standard deviation, and Ï2 is known as the variance.
The Acceptable Quality Limit, commonly referred to as AQL, is a method widely used to measure a production order sample to find whether or not the entire product order has met the client's specifications. The customer then has the data to make an informed decision to accept or reject the lot.
Otherwise, the process is said to be at a rejectable control level. In 2008 the usage of the abbreviation AQL for the term acceptable quality limit was changed in the standards issued by at least one national standards organization ( ANSI / ASQ ) to relate to the term acceptance quality level.